Trainer for aviators



Nov. 23, 1937. E. A. LINK, J 2,099,857-

TRAINER FOR AVIATORS Filed Aug. 14, 1936 l 11 Sheets-Sheet l INVENTOR. [aw/w AZ 1mm 11k.

- ATTORNEY.

1937- Y 1 E. A. LINK, JR l 2,099,857'

TRAINER FOR AVIATQRS I v Filed Aug. 14, 1956 11 Sheets-Sheet 2 IN V ENTOR. [aw/w /7. 1/11/45 JR.

ATTORNEY.

Nov. 23, 1937. E. A. LINK. JR

TRAINER FOR AVIATORS 11 Sheets-Sheet 5 Filed Aug. 14, 1936 I Y INVENTOR. [ow/Iv A. luv/r, r/k.

ORNEY.

Nov. 23, 1937. E. A. LINK. JR

TRAINER FOR AVIATORS Filed Aug. 14 1936 ll Sheets-Sheet 5 INVENTOR. [ow/z 14.1mm, J17.

BY ATTORNEY.

Nov. 23,1937. E. A. LINK, JR 2,099,857

TRAINER FOR AVIATORS Filed Aug. 14, 1936 ll Sheets-Sheet INVENTOR. Eawnv fi. Lmw, r/Ic ATTORNEY.

Nov. 23, 1937. E. A. LINK, JR

TRAINER-FOR AVIATORS Filed Aug. 14, 1936 ll Sheets-Sheet 7 INVENTOR. [owl/v A L nwr, J/a.

ORNEY.

- Nov 23,1937. E. A. LINK, JR

TRAINER FOR AVIATQRS 11 Sheets-Sheet 9 Filed Aug. '14, 1936 INVENTOR ATTORNEY,

Nov. 23, 1937. E. A. LINK, JR

TRAINER FOR AvIAToRs Filed Aug. 14, 1936 ll Sheets-Sheet lO- INVENTOR. fan/01 ,4. 1/1111, Jk.

NHE v Nov. 23, 1937. I E. A. LINK, JR 2,099,857

TRAINER FOR AVIATORS 7 Filed Aug. 14, 1936 11 Sheets-Sheet 11 INVENTOR. Env /1v )4, Law, r/k.

UNITED STATES PATENT OFFlCE TRAINER FOR AVIATOBS Edwin A. Link, 312,

Application August 14,

36 Claims.

My invention relates to trainers for aviators and is an improvement upon my prior Patent Number 1,825,462 issued September 29, 1931.

In the art of training pilots, particularly for i flying by instrument, I have found it possible to provide in a trainer, which essentially constitutes a miniature aeroplane mounted upon a universal support whereby the trainer can be rotated, tilted, and tipped in all normal flying positions of an aeroplane, means whereby the response of the trainer and of the essential instruments can be simulated exactly in accordance with the actual response thereof in an aeroplane in flight. This makes it possible for the training of pilots in instrument flying without hazard in all kinds of weather and at a very much reduced cost as compared with the same type of instruction if given in actual flight.

One of the principal objects of my invention is to provide an improved training device of this type wherein the pilot is placed under conditions simulating exactly those of an aeroplane in actual flight, and is provided with means whereby he can control'and correct the position and performance of the trainer in the same manner as if in actual flight.

One important feature of my invention lies in the provision of a throttle control and assembly in the trainer by means of-which the instru- 30 ments responsive to throttle control in an aeroplane and responsive to motor operation in an aeroplane, function in like manner in the trainer and under the influence of the throttle assembly unit.

A second important feature of my invention lies in the provision of means for causing the instruments registering air speed, vertical speed, and in addition, the sensitive altimeter to function in the trainer in a manner exactly simulating these same instruments in an aeroplane in flight.

Another important feature of my invention comprises a means'for deflecting the compass in the trainer in a manner to simulate actual compass performance in an aeroplane under all conditions of flight.

Still another important object and feature of my invention lies in the provision of means for causing the trainer to spin under certain circumstances of operation corresponding to similar circumstances and conditions if imposed upon a plane in actual flight. This means is also interrelated with the appropriate instruments on the trainer so that they perform, as a result of the spin, exactly as do the instruments of a plane under similar conditions.

Binghamton, N. 32'.

1936, Serial No. %,33

(Cl. sis-l2) Still another object of my invention lies in the provision of a motor driven mechanism for causing the trainer to assume various positions and angles corresponding to the effect of rough air on a plane in actual flight. 5

A further object of my invention lies in the provision of means for causing the turning of the trainer when one wing thereof is low, in simulation of an aeroplane in flight under like conditions.

Other objects and advantages will be apparent as the description proceeds, reference now being had to the figures of the accompanying drawings forming a part of this application and wherein like reference numerals indicate like parts.

In the drawings:

Figure l is a side view of my improved trainer in assembled condition.

Figure 2 is a top plan view of a portion of the supporting base for the trainer.

Figure 3 is a top plan view of the supporting structure for the trainer with the tilting bellows in assembled position. Also clearly shown in the figure is the turning motor for the rotatable support.

Figure 4 is a detail cross sectional view illustrating the assembly of the trainer supporting means and the main air duct therethrough for the various operating parts. This figure also illustrates the electric wiring connections for the radio equipment with which the trainer is equipped and also for the motor governing the air pump for operating the tilting bellows.

Figure 5 is a top plan sectional view showing in assembled relation within the trainer the various control valves and units for the operation of the trainer.

Figure 6 is a front view of the instrument board. or panel of the trainer.

Figure 7 is a detail view of the compass deflector.

Figure 8 is a detail side view of one of the control valves.

Figure 9 is a top plan view thereof, certain parts being broken away for clearness of illustration.

Figure 10 is a top plan view illustrating another of the control valves. 5

Figure 11 is a perspective diagrammatic view illustrating the general air system and connections with the various bellows units together with the controlling valves therefor.

Figure 12 is a diagrammatic perspective view illustrating the rudder control assembly and its connections to the various parts operated'thereby.

Figure 13 is a detail side view of the spin trip bellows.

Figure 14 is a perspective diagrammatic view of the instrument valve control assembly.

Figure 15 is a detail side view of the trainer in one position of control.

Figure 16 is a side view of the trainer in another position of control.

Figure 17 is a detail sectional view of the compensating connection between the trainer and its support for the operation of the control valves.

Figure 18 is a detail sectional view of one of the control valves.

Figure 19 is a side view of one of the instrument control valves.

Figure 20 is a fragmentary view similar to Figure 19 showing the partsin a different position of operation.

Figure 21 is a detail sectional view illustrating the instrument valve push rod.

Figure 22 is a front view of the stall and spin trip valve.

Figure 23 is a cross sectional side view of the stall and spin trip valve.

Figure 24 is an end view of the operating means for the spin trip valve.

Figure 25 is a sectional view thereof.

It should be borne in mind at the outset that this trainer is constructed to simulate as nearly as possible the actual appearance, feel, and maneuverability of an aeroplane, particularly when it is being operated under a hood, and is provided with standard aeroplane instruments, control stick, rudder, etc. so that the student pilot using the same may transfer from this trainer after receiving his course of instruction or after having had practical experience therein, to an actual plane and without confusion or strangeness, duplicate that which he has acquired by instruction and experience in the trainer. It is not a toy or plaything but is designed specifically for the purpose of teaching the art of instrument flying to already competent pilots.

The reference character I refers'generally to the fuselage of the trainer which simulates inininiature the fuselage of an aeroplaneand may be provided with the usual control surfaces and tall assembly of a plane. This trainer is supported upon a base frame 2 on the upper side of which is provided the fixed supporting cross 3 and through the center of which is secured the bearing housing 4 (see Figure 4). The bearing housing 4 is bolted as at 5 to the supporting cross 3 and carries the roller bearing rings 6 complementary to the bearing rings I carried by a rotatable supporting shaft 8 and between which rings are disposed the ball bearings 9. The shaft 8 is shouldered as at II! for engagement, being shouldered to receive the bearing ring 'I. These bearings are designed as thrust bearings as well as supporting bearings. The bottom of the housing 4 is flanged as at II to hold the outer ring 6. A cover plate I2 is provided over the top of the housing 4 and around the shaft 8. The shaft 8 is reduced in hickness as shown clearly in Figure 4, from the bearing housing downwardly and its lower end is received within a plug I3 suitably secured therein and projecting into the hollow shaft. The plug I3 is secured to the shaft 8 for rotation therewith and extending into the hollow plug I3 is a shouldered nipple I4 fixed with respect to the shaft and to which is secured one end of an air duct I5 communicating through the nipple and plug with the interior of the shaft 8. Lining the interior of the .hollow shaft B is a hollow tubing I6 of rubber ing 4. The belt bellows 25 carried or the like through which the flow of air controlling the various operations to be described takes place.

Still referring to Figure 4, the outside of the shaft 8 adjacent its lower end is provided with a plurality of electric contact rings II cooperating with which are fixed contact brushes I8 for a purpose to be described. Suitable electrical connection is made between the contact rings I1 and a series of stationary contacts I9 at a point within the trainer through the conductor cable 20 which passes upwardly within and through the hollow shaft 8.

Supported upon the upper end of the shaft 8 is a boss 2I shouldered at its top as at 22 to engage the top of the shaft'8. This boss is keyed to the shaft 8 for rotation therewith as by means of a set screw 23. Radiating outwardly from the boss 2| are the supporting arms 24 (see Figures 3 and 4) which rotate with the shaft 8 and which support the tilting bellows 25 for the trainer. A frame 26 connects the ends of the arms 24 to provide a housing for the bellows and to this frame at one point is secured a step 21 to facilitate getting into and out of the trainer.

Also supported by one of the arms 24 and braced to the frame 26 is an extension frame 28 supporting the double acting air motor 29 which serves to rotate the shaft 8 by means of a belt 30 extending from such motor around a pulley wheel 3I (see Figure 2) rigidly supported upon the top of the frame 2 and surrounding the bearing housrunning between the air motor 29 and the pulley wheel 3I is disposed between the fixed support members 3 of the frame and the rotatable arms 24.

The details of the air motor 29 (Figures 1 and operates in the opposite direction. The control of this reduced air to the motor is by means of the rudder and other means in the trainer through valves and connections to be described.

Referring again to Figures-1, 3 and 4. there is suitably bolted to the upper side of the boss 2I a spacing block 32 and to the upper side of ,this block is secured a bifurcated supporting bracket 33 provided with aligned pintles 34 pivotally mounted upon which is a swivel 35. Both the spacing block 32 and the bifurcated supporting bracket 33 are hollow and the air tube I6 extends upwardly therethrough and through an opening in the bottom 36 of the trainer. The swivel member encircles the tube I6 and is provided on opposite sides and at right angles to the pintles 34 with pintles 31 (see Figure l). Pivotally secured to these pintles 31 are downwardly depending arms 38 carried by a bracket 39 on the underside of the bottom 35 of the trainer. It will thus be seen that the trainer is mounted for universal tilting by means of the pivot about the pintles 34 in one plane and about the pintles 31 in a plane at right angles thereto. This permits the tilting of the trainer to any desired angle as well as providing for the rotation thereof through a complete 360 degree turn together with the shaft 8. Secured to the top side of each of the tilting by the arms 24 is a strap or plate 40 upon which is mounted an upwardly extending screw rod M, the upper end of which passes through the bottom of the trainer and is provided with a threaded ball nut 42 seated withtrainer fuselage in a suitable bearing opposite or rear end of the shaft is suitably in a socket 43 provided for each of the screw rods and by means of which the trainer-may be properly adjusted with respect to the base and yet permitted to freely tilt in response to the action of the bellows 25. It will be obvious that with this connection between the upper sides of the bellows 25 and the bottom of the trainer at positions forwardly and rearwardly of the center of the trainer and on each side thereof, operation of the bellows 25 to collapse or expand will result in corresponding tilting movement of the trainer.

In Figure 1 there is shown mounted within the base frame 2 a motor driven air turbine by means of which a suction force is created which communicates with the trainer through the duct 15 through the hollow shaft 8, tube l8, and the various flexible hose connections and valves within the trainer tobe described.

Within the trainer fuselage there is provided a control stick 45 secured upon a shaft 46 extending longitudinally oi'the trainen' mounted upon the shaft 45 for free pivotal motion in a plane longitudinal with the shaft 45, but is connectedso that side motion of the stick lateral to the shaft results in rotation of the shaft. The shaft 46 is supported at the front of the 41. The

supported in bearings (not shown) and has secured to its rear end, a collar 48 extending outwardly from which is a lever 49 having pivotally connected to ts end a link 50.

Suitably mounted in brackets 5| adjacent the vfront of the trainer is a shaft or bar 52 upon which are mounted rudder pedals 53, each of which is separately connected by cables 54 and 55 to the ends of arudder bar 56 pivotally supported at its center as at 51 to a fixed bracket 58 carried by a brace member 59 extending across the trainer.

The operation of that of the stick of an aeroplane, operation of the rudder pedals interior of the trainer is, of course,

the stick 45 simulates exactly as does also the and bar. The provided with a suitable seat conveniently arranged and fromwhich the operator can grasp the stick and reach the rudder pedals.

In front of the pilot in the trainer is an instrument panel 60 (see Figure 6) upon which are mounted the various fllghtunstruments such as the magnetic compass 8|, the artificial horizon 62, the sensitive altimeter 63, the radio compass 64, radio marker beacon 85, airspeed indicator 56, bank and turn indicator 61, vertical speed indicator 58, and gyro compass 69. Also provided on the panel 60 within easy reach ofthe pilot is a throttle member 18. As before stated the operation of the trainer by manipulation of the stick and rudder is such that the instruments register the result of such operation exactly the same as do the instruments of an aeroplane in actual flight. Referring now particularly to Figures 5 and 9;

it will be observed that centrally of the trainer a pipe 1| communicates with the upper end of the tube 15 comprising the main reduced air channel or duct from the vacuum turbine. This pipe 1| communicates through a' suitable connection 12 to a hollow manifold pipe 13. One end of the manifold 13 communicates with a rotatable valve member 14 cooperating with a' stationary valve member 15. The end of the manifold 13 entering the top element 14 of the valve communicates with an opening 16 centrally disposed therein and extending downwardly through a substantial part This stick isvice, the function of which will now As is known,-when an aeroplane in actual flight of the top element 14. Spaced from-this central opening 16 is an opening 1.1 extending from the underside of the-top element 14 of the valve upwardly for a substantial distance, and connecting the openings 16 and 11 is a duct or passage 18.

Disposed in the same radial plane with theopening 11 but located in the 15 of the valve, are

lower fixed element the spaced openings 19 and extending'from the top of such lower element downwardly a substantial distance and then having passages 8| (see Figure 9) communicating therefrom outwardly to the edge of valve member 15 and communicating with such passages are the pipe connections 82 and 83. Obviously rota; tion of the upper element 14 of the valve; to bring the opening 11 into registry with either one of the openings 19 or 80 will result in establishing reduced air communication between the manifold 13 and the pipes 82 or 83.

The rotation of the upper valve member 14 is caused, in one instance, by the operation of'the rudder pedals 53, through the links 54 and 55 to the rudder bar 56. With reference to Figure 9 iii it will be observed that there is a link 84 fixedly connected at one end as at 85 to the rotatable valve element 14. This link is connected at its' opposite end (see Figure 12) as at 85 to the lower end of an arm 81 pivoted as at 88 to a plate 89 carried by one end of a shaft 95. The 4 opposite end of the arm 81 has pivotally secured thereto one end of a link 9|, the opposite end of which is secured as at 82 to the rudder bar 56. Obviously therefore, pivotal movement of the rudder bar 56 will, through the parts just described, serve to rotate the valve element 14 to bring the opening 11 into registry with eitherthe port' 19 or port 88 depending 'upon the direction of movement of the rudder bar.

The. pipe connections 82 and 83 communicate through suitable flexible hose members 93 with the turning motor 29 (see Figure 3). Therefore the operation of the rudder bar in either direction serves to operate the turning motor 29 to rotate the trainer as heretofore explained.

Again referring to Figures 5 and 9, itwill be ,seen that in addition to the ports and openings just described, the upper'rotatable valve section 14is also provided with a second opening 94 extending from the underside of such element upwardly substantially through the same and communicating through a port 95 with the central opening 16. I

The stationary bottom valve eiement 15 is also provided with additional spaced openings 96 and 91 extending from the upper side of such element downwardly a substantial distance and provided 4 with lateral ducts 98 communicating with the peripheral surface of such unit and having connected thereto and in communication therewith the pipe sections 99 and 150. The some action occurs as before explained, namely, that when the upper element 14 is rotated, the opening 94 communicates with either the opening 95 or the. opening 91 establishing communication between the pipes 99 or I88 and the main source of reduced air.

The pipes 98 and I00 communicate. through hose members IN with a compass deflector debe described.

makes a turn, the magnet-c compass generally turns inaccurately during the turn of the plane to the fact that the compass is pivotally mountplane in the air, when the plane is banked for a turn, this angle'is changed and if the plane is, for instance, in the northern hemisphere and heading north and makes a turn to the right the angle of the magnetic force on the compass is changed to an extent that the compass swings slightly temporarily to the left. This is due to the fact that the compass card is clamped in heavy liquid so that when the plane is first banked, the card assumes approximately the same angle until such time as it can change its position through the damping fluid. This creates the angular magnetic pull on the vcard'during such.bank.

In the trainer, however, which is, of course, on the ground, the lines of magnetic force operating upon the compass are not pulling angularly as in the case of the plane in the'air, and therefore, the same condition does not apply when the trainer is banked and turned. In order to simulate in the trainer this exact operation of the compass in actual flight, a compass deflector is provided which consists (see Figures 7 and 12) essentially of an arm I02 pivotally mounted as at I03 to an adjustable base I04, the upper free end of the arm I02 carrying a magnetic bar I05..

This bar is normally held. in vertical position by means of two leaf springs I06 applying their force against opposite sides of the bar, such springs resting intermediate their ends against a fixed stop member I01. A frame member I08 supports the springs I06 and also the stopmember I01.

Secured to the frame I00 are oppositelydisposed bellows I09 and H0, the free sides of which are secured to thearm I02. The two hose members IOI from the valve member '15, communicate with the bellows I 09 and H0.

This compass deflector is positioned in the trainer directly beneath. the magnetic compass GI and normally the influence of the magnet on the compass is neutral. The adjustable base I04 makes possible the flne, adjustmentof the magnetic bar I05 to the exact center of'the compass so as to neutralize its influence under normal conditions.

It will be clear now that upon operation of the rudder and rotation of the valve'element 14 to turn the trainer in either direction, the opening 94 (see Figure 9) will uncover either the opening 96 or the opening 01, depending upon the direction of turn, establishing reduced air communication between the main channel and through one of the hose connections I 0| to one of the bellows I00 or 0, causing the same to collapse and pulling the magnetic bar I05 laterally with I i respect to the compass whereby to influence the compass in exactly the same manner as the same is influenced by the angle lines of magnetic force acting on a plane in actual flight as previously described. v

Referring again to Figure 9, it will be observed that the top rotatable valve element I4 is provided with two oppositely disposed openings III extending completely through the movable elemeat 14 and communicating at the top with the atmosphere. The purpose of these openings is to permit entry of atmospheric pressure into the opening or duct opposite that through which reduced, air communication is being established. For instance, if the valve member '14 is turned to the left in, Figure 9' to bring the opening I1 into registry with the opening I. whereby to will register with the opening 8| admitting atmospheric pressure to such opening and through the line 83 thereof to render more effective and more immediate the reduced air force or vacuum effect through the opening 19 and line 82. 1

Referring now to Figures 6, 15 and .16, the operation of the trainer will be described as a result of the pivotal movement of the control stick forwardly or rearwardly simulating the diving and climbing control of a plane in flight. With reference to Figure 12 it will be observed that the stick 45 is pivotally mounted intermediate its ends as at H2 to a block II 3 rigid with the shaft 46. The lower extending end of the stick 45 has pivotally secured thereto as at II4 one end of a link H5, the opposite end of which is secured as at H6 to the upper rotatable portion II I of a valve such as is shown in Figure 10, the bottom portion II8 of the valve being flxed. Obviously therefore, movement of the stick forwardly or rearwardly in a direction longitudinal of the shaft 46 will result in rotating the valve part II! in one direction or the other. The upper valve part I I1 is provided centrally with an opening IIS communicating through a pipe section I20 (see Figure 12) with the reduced air manifold I3. A duct I2| leads from the central opening H9 of the valve to an opening I22 near the peripheral edge of the upper part of the valve. The bottom or fixed part II8 of this valve is provided with two spaced openings I23 and I24 with which the opening I22 is adapted to be seelectively registered depending upon the direction of rotation of the top part of the valve. The top valve portion II! is also provided with two oppositely disposed openings I25 extending en-- I 24 admitting atmospheric-pressure to the open- Communicating with the opening I24 is a pipe' or hose line I26 and communicating with the opening I22 ls a pipe or hose line I21, the former communicating with the forward bellows 25 and the latter communicating withthe rearward be1- lows 25 disposed in longitudinal alignment with the fuselage of the trainer. (See Figure 11.) Obviously if the stick is pushed forward a vacuum is admitted to the forward bellows 25 serving to collapse the same and causing the trainer to tilt its nose downwardly. If the stick is pulled rearwardly from central position, vacuum is admitted to the rearward bellows 25causing it to collapse and causing the trainer to tilt its nose upwardly, in simulation of the action of response to similar movements of the regular control stick. It will be understood, of course,

an aeroplane in In order that the trainer may be caused to tilt laterally or sidewise, or to bank in exact simulation of an aeroplane in flight, the side bellows scribed in connection with the forward and rearward tilting mechanism. This valve Illa has a fixed portion Ba and the entire valve is suitably rigidly supported by means of a bracket I29 secured to a fixed part of the trainer. The details of this valve are not shown separately as they are identical with the valve shown in Figure 10 and there are provided from the outlet ports of this valve, pipe or 'hose lines H39 and I3I,

the former communicating with one of the side bellows 25 and the other communicating with the other bellows 25. The source of reduced air pressure is provided for. this valve through the pipe I32 communicating with the end of the main manifold 31. Obviously therefore, move; ment of the stick .45 to one side or the other, results in rotation of the shaft 45, this in turn, through the arm 49 and link 50, causing rotation of the valve part IIIa to bring the valve ports into selective'registry with the ports in the fixed part of the valve to admit the reduced air pressure to the side bellows and causing the same to collapse, thus tilting the trainer laterally to one, side or the other.

As is known, in the actual operation of an aeroplane in flight, if the plane is banked either to the right or left without simultaneously operating the rudder to turn the plane, the banking of the plane automatically results in a slight turning of the plane in the direction of the bank. In order to simulate this condition in the trainer, there is provided (see Figure 12) a fixed arm I33 secured to one of the supporting arms 24. of the trainer. The lower end of this arm is swiveledand made rotatable in any suitable manner (not shown) and the upper end of the arm is pivotally connected as at I34 with one end of a short arm I35 fixed to the shaft 90 carried by. the trainer through means of brackets I36 suitably mounted within the fuselage of the trainer. Obviousiy therefore, as the trainer is banked to one side or the other, the relative movement between the .fixed arm I33 and the short arm I35 and shaft 90, due to such banking movement, causes the arm I35 to rotate the shaft 90 in one direc-. tion or the other, this resulting in causing the link 84 to actuate the rudder control valve I4 without any movement on the part of the rudder bar 56 itself by the operator and causing reduced air pressure to be admitted to one side or the other of the turning motor 29 to cause a turning of the trainer.

It will be understood, ofcourse, that an aeroplane in 'actual flight through the air encounters varying types of air resistance such as head winds, tail winds, up drafts and down drafts. These are oftenvariable and react upon the plane in a manner to cause it to lift or dropv or tilt or turn in a bumpy manner. In order to simulate such conditions in the trainer, I have provided means whereby the various bellows 25 are automatically caused to expand by admission of atmospheric pressure thereto in an irregular and unexpected manner. This mechanism comprises (see Figures '5 and 11) an electric motor I3] suitably mounted within the trainer and a gear drive I38 from such motor to a shaft I39 upon which are a plurality of cams I49 irregularly arranged on the shaft and adapted to engage, upon rotation of the shaft, with movable valve elements I4 I The shaft I39 is suitably supported in the trainer by means of brackets I42. Each valve I4I has a pipe or hose line connection I43 to one of the outlets of each of the 'valves I4, III, Illa. These valves I4I when opened by the cams I4Iladmit'atmospheric pressure through the valves and through the lines I63 and thence throu h the connecting hose lines between the valves I4, III, IIla. to the bellows 25 and to the turning motor 29. The admission of this atmospheric pressure is momentary only, depending upon the length of the cam engaging the movable part of the valves I II. Consequently as each valve is caused to open, it admits atmospheric pressure to the particular bellows involved causingit to expand momentarily and thus upsetting the equilibrium of the trainer and reproducing on'the trainer the rough air condition previously described.

Obviously the particular type of valves I4I which may be used for this purpose is variable and any desired type may beselected. The particular form has not been shown in detail for that reason.

Obviously too, the operation of this rough air means is selective inasmuch as the motor I31 can be turned on at will. In this connection also any suitable adjustment maybe provided for the supporting means for the valves I4I bywhich they can be disengaged entirely from the cams I40 and also by means of which the amount of opening of such valves by the cams can be controlled. Details of this adjusting mechanism are not shown.

Referring again to an aeroplane in actual flight for comparison, as the plane proceeds in flight the usual air speed indicator registers on that instrument the air speed of the plane. Likewise as the plane dives or climbs the vertical speed indicator registers showing ascent or descent. Likewise, the altimeter registers the fact of climb or descent.

Likewise, the air speed indicator, with a constant throttle setting, shows an increase when the plane is descending and a decrease when the plane is climbing. Similarly the altimeter registers such descent and ascent. In addition the air speed indicator, registers a reduction in air speed when the plane is climbing and an increase in speed when the plane is diving.

Furthermore, the" operation of these instru-- ments, particularly the air speed and vertical speed indicators, is responsive to the operation of the throttle and motor on the plane, that is, an increase in speed of the motor is registered on theair speed indicator and the vertical speed indicator in accordance with the position of the plane.

- thereof an upstanding arm I44 swiveled at its lower end to the rigid support and pivotally connected at its upper end with the bottom of the trainer. This arm is'shown in detail in Figure 17 and is in the form of a cylinder I45 within which is slidably disposed a rod I46 projecting through the bottom of the cylinder and has suitable swivel connection with the rotatable trainer support. Disposed within the casing I45 is a sleeve I41 secured rigidly therein. The rod I46 passes through this sleeve and carries within the sleeve a piston I48 slidable with the rod through the sleeve I41. At either end of the-sleeve there is provided a bushing I49 loosely mounted around the rod I 46 of a size to engage the ends of the sleeve and not pass thereinto. A coil spring I50 encircles the rod I46 below the sleeve I41 extending between a collar II on the rod I46 and the underside of the sleeve I41; A second coil spring I52 encircles the rod I46 above the sleeve I41 and engages at its upper end against a collar I53 secured to apin I54 connected at its upper end. with the trainer. The lower end of the coil spring I52 engages against the upper end of the sleeve,

I41. The rod I46 terminates about midway between the upper end of the sleeve I41 and the upper end of the casing I45.

Obviously if the trainer assumes the climbing position shown in Figure 15, the rod I46 together with the collar I5I will slide upwardly through the sleeve I41 compressing the spring I50. If the movement of the trainer to this climbing position is extreme, the piston I46 within the sleeve will slide upwardly through the sleeve compressing the spring I52 through the medium of the slidable bushing I49 and thus take up any result is that the rod I54 of the arm I44 moves upwardly and through its connection at I55 with an arm I56 secured at its opposite end to a shaft I51 will cause such shaft to turn to the left in Figure 14. Secured to this shaft I51 at its opposite end is an arm I58 carrying a stub shaft I56 having pivotally mounted thereon as at I60 one end(of an arm I6I. The opposite end of this arm has connected thereto one end of a link I62 the opposite end ofwhich is secured to an operating rod indicated generally in Figure 14 at I63, the details after.

Continuing the description of the function of these parts with the trainer in the position shown of which will be described herein Figure 15.. rotation of the shaft I61 to the left in Figure 14 will cause the movement to the left of the pintle I59 and cause the arm -I6'l to rock 'about'the point l64 (hereinafter described) resulting in pulling the link I62 to the right and moving the operating rod I66 to the right. The operating rod I62 has operative connection with two valve operating arms I65 and I66. the former actuating a "diving valve I61, the latter operating a "climbing valve I66. Valve I61 comprises a block suitably mounted upon a bracket I66 and is provided with an opening I10, the outer end of which is threaded as at "I to receive a threaded 75 needle valve stem I12 carried by the end of the operating arm I65. This threaded valve stem is provided at its inner end with a needle valve portion I13, cooperating with a reduced portion I14 oi the valve opening. This reduced portion communicates with a transverse duct I 15 with which is connected a pipe or hose line I16 connected to an equalizing tank I11. The valve opening I is also provided with a transverse duct I16 with which communicates a short pipe I19 communicating directly with the atmosphere. The threaded valve stem I12 is a lefthand thread and it will be clear that when the operating arm I65 is moved to the right or left as indicated in Figure 14, the valve stem will be rotated to move the needle valve into or out of closing position with respect to the suction channels I and I16.

The climb valve I68 is identical in every respect with the valve I61 just described'andthe valve shown in Figure 23 is intended to show the detail of both of these valves. In other words,

the climb valve I68 also has a screw threaded needle valvetherein dperated' by the arm I66, excent in this case the screw valve stem is a right hand thread instead of a left hand thread. Communicating with the valve opening in the valve I68 is a pipe line connection I80 connected at its opposite end with the main vacuum manifold 31 (see Figure 5). The valve I66 also has a communicating pipe and hose line I8I directly to the equalizer tank I11. l

Continuing now the functional description with the trainer in its climbing position, we have seen that the valve operating rod I63 is moved to the right in Figure 14. This results in turning the needle valve I12 in the valve I61 to closed position, thereby closing communication from such valve with respect to the equalizer tank I11. The same movement of the rod 1 63 serves to open the needle valve in valve I63 thereby establishing suction communication .through the ,valve and through the line IBI into the tank I11. It should be stated here that communicating with the tank I11 by means of a hose line I82 is the altimeter 63. Also communicating with the tank I11 through a hose line I83 is the vertical speed indicator 68. Obviously therefore, with suction established through the valve I66 to the tank I11 and the altimeter and vertical speed indicators, because of the climbing position of the trainer, the suction force acting upon these two indicators will result in their registering climb and rate of climb (insofar as the vertical indicator is concerned) depending upon the amount of suction force so provided-this in turn depending upon the angle of the climbing position of the trainer.

- The amount of climb will be registeredjon the altimeter depending upon the length of time during which the traineris held in the climbing position. Conversely, if the trainer is tilted to descending position, shown in Figure 16. the reverse action of the valves I61 and I66 will result as follows. With the trainer in this descending position. the rod I54 will serve to rotate-the arm I56 downwardly, thus rotating the shaft I51 to the right and carrying with it the pintle I56 and rocking the arm I 6I about the pivot point I64, the lower end ofthe arm I6I now moving to the left in Figure 19 and causing the link I62 to move the operating rod I63 to the left. This movement through the arm I results in opening the needle valvein the "diving valve, I61 admitting atmospheric pressure through the port I 16 and through the line I 16 to the eq'ualizertank I 11. Simultaneously the' operating arm I66 operates the nee- 'dle valve in the "climbing" valve 188 to close the communication between the suction line I88 and the tank I11. The result is that the changing air condition in the tank I11 reacts on the altimeter 63 and vertical speed indicator 88, they showing descent, and the vertical speed indicator showing a speed of descent commensurate with the amount of tilt of the trainer and the altimeter showing the amount of descent commensurate with the time the trainer is held in such position. Obviously if the trainer is maintained in level flight position, the vertical speed indicatorwill remain at zero due to the fact that both of the valves I81 and I88 are in closed position. The altimeter will, for the same reason, remain at whatever reading the air condition in the tank at the time level positioning of the trainer is accomplished, compelled due to the amount of suction within the tank.- Any variation of the position of the trainer either up or down will instantly register on these two instruments in the manner just explained, and is proportionate to the amount of movement of the trainer.

Referring now tothe means for causing the.

Z air speed indicator 66 to register in response to the'position of the trainer in accordance with its climb or descent position, reference is again had to Figure 14. There is provided a bellows I84, one side of which is fixed, and communicating with this bellows is a hose line I85 connected with the hose line I88communicating with the main suction manifold- 81 and also communi cating with the bellows I84 is a hose line I88 leading into a dampening tank I81 from which a hose line I88 communicates with the air speed indi- -cator '66. The movable side of the bellows I88 carries a needle .valve I89 cooperating with a valve member I98 carried by the fixed side of the bellows and communicating with the suction line I85.

The movable side of the bellows I 88 is connected by a coil spring -I9I to, one end of a link I92, the opposite end of which is connected to the lower end of an arm I98 pivoted at I94. On

;4 5 the opposite side of the pivot I94 from the link I92 is a link I95 connected at its opposite .end with the arm I6I at a point above the pivot point I88.

Now if the trainer is in a climbing position as '50 shown in FigurelS, the shaft I51, as before explained, is rotated to the left causing the pintle I59 and the upper end of the arm IGhto move to the left, thus exerting a pull to the left on the link I95 rocking the arm I93 about its pivot I94 .55 and causing the link I 92 to move to the right. This releases the tension on the spring I9I and permits the bellows I84 to collapse resulting in the needle valve I89 closing the communication to the suction line. The tank I81 is provided with a :60 small orifice I96 providing for a very slow admission of atmospheric pressure tothe tank. When the bellows I84 is collapsed and the suction force to the tank I81 is closed, the atmosphere slowly entering the tank I81 through this orifice causes.

:05 the air speed indicator to show a falling oif due to the slow reduction in suction force acting upon such indicator. 7

- If, on the other hand, the trainer is tilted downwardly as shown in Figure 16, the reverse action 70 of the parts just described occurs, causing the needle'valve I89 to open the communication to the suction line and through the bellows re-establishing the suction force within the tank I81 whereupon the air speed indicator responds showing an increase in air speed. The amount of increase and decrease in the showing of the air speed indicator depends upon the speed at which the valve is opened by the tilting of the trainer and upon the length of time it remains in its tilted position.

Again referring to an aeroplane in flight for comparison,it is known that if an aeroplane is climbed to such an extent that through the lack of power of the motor it reaches a point where it can no longer climb at that angle, the plane begins to lose altitude and the vertical speed indicator and the altimeter register such loss of altitude and the rate thereof. At such a point the forward speed of the plane, if the plane is held at the same climbing angle, becomes less than the vertical descent speed thereof. Also under such conditions when the forward speed of --.e

plane reaches the stalling point, that is, the point at which the weight of the plane overcomes the forward speed and the lifting power on the plane, then the plane goes into a spindue to lack of control, this spin being characterized by the nosing downwardly of the plane and the turning thereof. I have provided in my improved trainer, means for simulating exactly these conditions and movements of a plane in actual flight and in registering on the air speed indicator, vertical speed indicator, and altimeter, the conditions just described, and in addition, bring about the actual rotation of the trainer. Furthermore by the controls provided in the trainer and previously described through the rudder and stick operations,

' it is possible for the student pilot to recover from a stall and spin in exactly the same manner as in an aeroplane in flight.

This means for simulating the stall and spin of a plane in the trainer comprises (referring again to Figure 14 and also to Figures 22 and 23) a valve I91 consisting of a block provided with an opening I98 therein threaded adjacent one end as at I 99 to receive a threaded valve stem 288 provided at its inner end with a needle valve 2M cooperating with a reduced portion 282 of the passage I98 and which reduced portion communicates through a duct 283 with a pipe line 284 extending to and communicating with the equalizer tank I11. Communicating with the passage I98 is a duct 285 communicating through a pipe 286 with the atmosphere. The valve block I91 is suitably secured to a bracket 281 secured to a fixed part of the trainer.

The opposite end of the valve stem 288 is provided with an enlarged portion 288 having a small opening 289 therethrough adapted to communicate in one position of rotation, namely, the

open position shown in Figure 23, with ports on either side of the valve block I91. One of these ports 2I8, (see Figures 14 and 22) communicates with the trip bellows of the spin assembly shown in Figure 12 and to be described in detail shortly. The other port 2 communicates with the hose line I88 connected with the main section manifold 31.

The outer extending end of the valve stem 288 carries an arm 2 I 2, the upper end of which is provided with a weight 2I3.

Disposed on either side of this end of the valve I91-are arms 2 of a bracket 215, the upper ends of which arms are provided with adjusting screws 2I'6 in alignment with the arm 2I2 and against which such arm is adapted to engage.

The normal position of the needle valve 28I is closed and in such position the arm 2 I2 is in the dotted line position shown in Figure 22.

Referring now to Figure 14, it will be noted that connected to the upper end of the arm I 93 is one end of a link 2 I 1, the opposite end of whiEh is connected as at 2 I8 with the upper end of an arm 2i9, pivoted at 220. The lower end of the arm 2 I 9 has secured thereto one end of a link 22I the opposite end of which is provided with two adjustable pins 222 adapted to be disposed in sepa rated relation at a desired distance with respect to a pin 223 carried upon the valve operating arm H2 and which is disposed between the pins 222.

The connection between the link 2" and the arm 2I9 is through a sleeve 224 slidable on such link between the coil springs 225 whereby gradual and resilient force is applied to the arm 2I9.

Again assuming that the trainer is in the climbing position of Figure and remains in such position until such time as the bellows I84, which control the actuation of the air speed indicator, reaches a predetermined position of collapse, due to the operation of the elements previously described, and with the needle valve I89 in substantially closed position with respect to the suction line I85, this corresponding to the stall situation of an aeroplane in actual flight, the link I92 rocks the arm I93 on its pivot I94 causing the link 2" to rock the upper end of the arm 2 I9 to the left in Figure 14 resulting in moving the lower end of the arm 2 I 9 to the right and at a predetermined time, governed by the setting of the pins 222 on the link 22I, the end pin 222 will engage the pin 223 on the valve control arm 252 causing the same to move to the right in Figures 14 and 22 to gradually open the needle valve 2M to admit atmospheric pressure through the port 295 and hose line 204 to the tank I11. This results in the vertical speed indicator and the. altimeter showing descent exactly as it happens in an aeroplane in flight.

When this condition prevails for a predetermined length of time the valve operating arm 2I2 continues its movement to the right and when it moves past center, the weight 2I3 on tht upper end thereof causes such arm to quickly drop the rest of the way to the right against the screw stop EEG and in this position the port 299 in the portion 2&8 of the valve stem registers with the line 2% I to the main suction line and also with the line 259 to the trip bellows of the spin assembly, causing the trainer to turn the same as an aeropiane does in a spin.

It will be understood, of course, that during the movement of the needle valve I to open petition by the movement of the control arm 2I2 to the right in Figure 22, the opening of the comrnunicationv between the atmosphere and the tank 111 shows on the vertical speed indicator 68 a steady decrease in rate or climb until it reaches zero and then for a short time a steady increase in rate of descent, this continuing until the valve arm 2I2 falls over under the influence ot the ,plane stalls, it immediately goes into a spin in e which the plane begins to rotate or turn. Means are provided in the trainer for causing the trainer to turn in similar fashion promptly upon the movement of the valve I91 to open position and with the port 209 registering with the lines 2m and 2 shown in Figure 14.

causing the valve I91 to rotate to the position shown in full lines in Figure 22, thus opening the communication through the port 209 in the valve I91 to the suction line through the pipe2l I, this suction is communicated through the hose line 2I0 to a bellows 224 (see Figures 12 and 13) Obviously admission of suction to the bellows 224 causes the same to collapse. This bellows is rigidly mounted in any suitable inanner upon the shaft 90,and directly between two oppositely disposed bellows 225 and 226. These bellows 225 and 226 have their rigid sides connected together and to the shaft 90 by means of plates 221.

The bellows 224 carries on its movable side a link 228, to the outer end of which is pivotally secured a lever 229 pivo'tally mounted intermedi- 4 ate its ends as at 230 to one end of a rigid arm 23! secured to the shaft 90. The shaft 99 carries a lock arm 232 rigid therewith and provided at its free end, with a notch 233 adapted to receive the free end of the lever 229. lever 229 is in looking position, that is, with the bellows 224 in expanded position, the shaft 90 is locked against turning. If, however, the bellows 224 are collapsed in the manner previously described through the operation of valve I91, the lever 229, rocked on its pivot 230 to the position shown in dotted lines in Figure 13 disengages the locking arm 232 leaving the shaft 90 free to rotate.

Each of the bellows 225 and 226 carries an ex- Obviously when the tending arm 234 pivoted to the ends of which are 4 Obviously 56 causing pivoting of the rudder bar depending upon which of the bellows is collapsed. Obviously the pivoting of the rudder bar 56 results in turning the trainer in the same manner as previously described and through the same elements including the turning motor, as previously explained in connection with the operation of the rudder and rudder bar. This then causes the trainer to simulate an actual aeroplane going into a spin.

Means for collapsing the bellows 225 or 226 comprise a valve 236 (see Figure 12) similar in every respect to valve I91 in thatit is provided with a pendulum type operating arm 231 provided with a weight 238 on its ends. The valve is provided with a port 239 which, when the valve is in one angular position, such as for instance, shown in Figures 12 and 24, opens communication through a hose line 240 to the lower bellows 226 and when in the opposite angular position opens communication through hose line 2, to bellows 225. A hose line 242 communicates with the valve 236 and with th suction line I89.

A suitable supporting bracket 243 is provided with arms 244.which serve as stops for the valve arm 231 and between which it swings.

The valve am 231 is Ireeto swing back and forth between the stops 244 as the trainertilts from one side to the other. Obviously, the swinging of the arm 231 and the operation of the valve 236 is ineffective to collapse either of the bellows 225 or 226 so long as the locking lever 229 is in engagement with the lock arm 232, the amount of suction force admitted to the bellows being insuflicient to overcome this look. When, however, the trainer has reached the stalling point as previously described, through the prolonged climbing attitude thereof, or through the action of the throttle, to be described, then the operation of the valve I9'I results in the unlocking of the bellows 225 and 226 whereupon the trainer is caused to turn in whichever direction the trainer is 1 tilted at the time or was tilted last previous to time the pilot in the trainer applies the opposite rudder to the direction of turning through the rudder bar 56, link 9|, and arm 81. Also the valve arm 231 with its weight 238 is drawn to the opposite side and against the opposite stop 244 by actuation of the rudder bar through means of an arm 249 (see Figure 5) the end of which is positioned to engage the arm 231 and cause the same to 'swing in whichever direction the arm 249 is turned by the rudder bar. This immediately causes whichever of the bellows 225 or 226 which has been collapsed to be again expanded so that when the shaft is rotated by operation of the rudder bar to a position shown in Figure 12, the locking lever 229 can again assume its locking position in the notch 233 thereon, the spin trip bellows'224 having been again expanded by the restoration of the valve I9Ito normal position.

As is well known, an aeroplane in actual flight responds to the throttle control by showing on the instruments a decrease in air speed or an increase thereof, and of course, depending upon the position of the-plane, that is, whether climbing or otherwise. I have provided means in the trainer for simulating exactly the registry of the instruments of an aeroplane under throttle control.

The throttle control means is shown in Figure 14 and in which figure the throttle III is shown connected by any suitable flexible connecting means 245 to one end of a lever 246 pivoted at its opposite end 241. Intermediate its ends the lever 246 has connected thereto a link 248, the opposite end of which is connected to the arm I6I at I64, previously described as the pivot point of such arm I6I. Obviously, so long as the throttle arm 246 is set in one position, the point I64 on the arm I6I can serve as a pivot or turning point for such arm. However, upon moving the throttle inwardly or outwardly and thus rocking the arm 246 on its pivot, the link 248 serves to rock the arm I6I about its pivot I60 on the stub shaft I59. This movement of the arm I6I in either direction, serves to rockthe arm I93 about its pivot I94 and causes the same operations exactly through the links 2" and I92 and the arm 2I9 and link 22!, as previously described,

means that the operation of the throttle to increase or decrease the assumed speed of the motor results in the air speed instrument, the vertical speed instrument, the altimeter, and the stall and spin controlling mechanism, all to register and function in the manner which has been previously described and which simulates exactly the action of a plane in flight.

For instance, in level flight the actuation of the throttle to the increased speed position causes the air speed indicator to show and register an increased speed. Conversely, moving the throttle in the'opposite direction results in a registration of loss of speed on that instrument and continued loss of speed will, of course, register on the altimeter as the trainer theoretically loses altitude. S milarly the vertical speed indicator will then show the loss of altitude.

Likewise, if the trainer is in a climbing position and the instruments show a loss of speed to the point of stall, operation of the throttle to" theoretically increase the air speed will not only register on the instruments but will prevent the operation of the stall mechanism.

It will thus be seen that I have provided a training device for teaching and practicing flying by instrument in a manner to simulate almost exact conditions of actual flight and without leaving the ground. Of course, changes may be made in details of construction and arrangement of parts without departing from the spirit and. scope of my invention I do not limit myself, therefore, to the exact form herein shown and described other than by the appended claims.

I claim:

tating said frame around a vertical axis, means for tilting said frame in simulation of an aeroplane in flight, a compass in said frame responsive to the directional positions thereof, and means associated with said compass and operable by the tilting and turning of said frame for deflecting said compass in simulation of the action of a compass in an aeroplane banking and turning in flight.

2. A trainer comprising a frame, means for rotating said frame around a'vertical axis, means for tilting said, frame in simulation of an aeroplane in flight, a compass in said frame responsive to the directional positions thereof, and means associated with said compass and operable by the tilting and turning of said frame for deflecting said compass in simulation of the action of a compass in an aeroplane banking and turning in flight, said means comprising a magnetic deflector normally disposed for neutral influence on said compass, and movable by tilting of the frame laterally to influence said compass to turn in the direction of and during said tilting.

3; A trainer comprising a frame, means for rotating said frame around a vertical axis, means for tilting said frame in simulation of an aeroplane in flight, a compass in said frame respon-z sive to the directional positions thereof; means associated with said compass and operable by the tilting and turning of said frame for deflecting said compass in simulation of the action of a,

1. A trainer comprising a frame, means for ro- 

